Merge #15744: refactor: Extract ParseDescriptorRange

510c6532ba Extract ParseDescriptorRange (Ben Woosley)

Pull request description:

  So as to be consistently informative when the checks fail, and
  to protect against unintentional divergence among the checks.

ACKs for commit 510c65:
  meshcollider:
    Oh apologies, yes. Thanks :) utACK https://github.com/bitcoin/bitcoin/pull/15744/commits/510c6532bae9abc5beda1c126c945923a64680cb
  MarcoFalke:
    utACK 510c6532bae9abc5beda1c126c945923a64680cb
  sipa:
    utACK 510c6532bae9abc5beda1c126c945923a64680cb

Tree-SHA512: b1f0792bfaa163890a20654a0fc2c4c4a996659916bf5f4a495662436b39326692a1a0c825caafd859e48c05f5dd1865c4f7c28092be5074edda3c94f94f9f8b

4 files changed, 23 insertions, 16 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 3d0fa8eb2b..5db3a6c987 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -2244,8 +2244,7 @@ UniValue scantxoutset(const JSONRPCRequest& request)
                 desc_str = desc_uni.get_str();
                 UniValue range_uni = find_value(scanobject, "range");
                 if (!range_uni.isNull()) {
-                    range = ParseRange(range_uni);
-                    if (range.first < 0 || (range.second >> 31) != 0 || range.second >= range.first + 1000000) throw JSONRPCError(RPC_INVALID_PARAMETER, "range out of range");
+                    range = ParseDescriptorRange(range_uni);
                 }
             } else {
                 throw JSONRPCError(RPC_INVALID_PARAMETER, "Scan object needs to be either a string or an object");
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index 7327d6a1b0..7008a83143 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -24,6 +24,7 @@
 #include <warnings.h>
 
 #include <stdint.h>
+#include <tuple>
 #ifdef HAVE_MALLOC_INFO
 #include <malloc.h>
 #endif
@@ -215,18 +216,7 @@ UniValue deriveaddresses(const JSONRPCRequest& request)
     int64_t range_end = 0;
 
     if (request.params.size() >= 2 && !request.params[1].isNull()) {
-        auto range = ParseRange(request.params[1]);
-        if (range.first < 0) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Range should be greater or equal than 0");
-        }
-        if ((range.second >> 31) != 0) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "End of range is too high");
-        }
-        if (range.second >= range.first + 1000000) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Range is too large");
-        }
-        range_begin = range.first;
-        range_end = range.second;
+        std::tie(range_begin, range_end) = ParseDescriptorRange(request.params[1]);
     }
 
     FlatSigningProvider key_provider;
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index e329ff7e46..9cdb22001f 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -8,6 +8,8 @@
 #include <tinyformat.h>
 #include <util/strencodings.h>
 
+#include <tuple>
+
 InitInterfaces* g_rpc_interfaces = nullptr;
 
 void RPCTypeCheck(const UniValue& params,
@@ -654,7 +656,7 @@ std::string RPCArg::ToString(const bool oneline) const
     assert(false);
 }
 
-std::pair<int64_t, int64_t> ParseRange(const UniValue& value)
+static std::pair<int64_t, int64_t> ParseRange(const UniValue& value)
 {
     if (value.isNum()) {
         return {0, value.get_int64()};
@@ -667,3 +669,19 @@ std::pair<int64_t, int64_t> ParseRange(const UniValue& value)
     }
     throw JSONRPCError(RPC_INVALID_PARAMETER, "Range must be specified as end or as [begin,end]");
 }
+
+std::pair<int64_t, int64_t> ParseDescriptorRange(const UniValue& value)
+{
+    int64_t low, high;
+    std::tie(low, high) = ParseRange(value);
+    if (low < 0) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Range should be greater or equal than 0");
+    }
+    if ((high >> 31) != 0) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "End of range is too high");
+    }
+    if (high >= low + 1000000) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Range is too large");
+    }
+    return {low, high};
+}
diff --git a/src/rpc/util.h b/src/rpc/util.h
index b5b5789253..e4fa8fc3d7 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -81,7 +81,7 @@ RPCErrorCode RPCErrorFromTransactionError(TransactionError terr);
 UniValue JSONRPCTransactionError(TransactionError terr, const std::string& err_string = "");
 
 //! Parse a JSON range specified as int64, or [int64, int64]
-std::pair<int64_t, int64_t> ParseRange(const UniValue& value);
+std::pair<int64_t, int64_t> ParseDescriptorRange(const UniValue& value);
 
 struct RPCArg {
     enum class Type {